2 MBX servers, Single DAG, Multi Database, Multi Site Active/Active HA ... (Full Version)

All Forums >> [Microsoft Exchange 2010] >> High Availability



Message


luke.denham -> 2 MBX servers, Single DAG, Multi Database, Multi Site Active/Active HA ... (12.Oct.2010 8:52:39 AM)

Hi,

I am considering the following config for Exchange 2010 SP1:

MBX01 - Site A
MBX02 - Site B
Single DAG with two databases, 1 active on each MBX0x server and replicated to the other (so 4 copies in total)

In the event of one server failing the other would host both active databases.

Now DAC supports a two member DAG in SP1, how does DAC support the loss of either data center ... Would I have to manually activate the passive database in the remaining data centre?

It's not clear to me in any of the documentation whether it is a supported configuration to have 2 databases (active/active) across two data centres using only two mailbox servers.

Welcome your comments on this ...




Danofre -> RE: 2 MBX servers, Single DAG, Multi Database, Multi Site Active/Active HA ... (21.Oct.2010 1:18:56 PM)

Should work fine. The DAG will failover the DB to the other MBX server that is still live. One DAG with 2 DBs... just active on 2 different servers. I typically run 3 copies.
2 MBX servers in each DC. One DAG:
Lets say 20 DBs:
Server 1 Site 1 hosts 5 DBs Active. 5 passive
Server 2 site 1 hosts 5 DBs active 5 passive
Server 1 Site 2 hosts 5 DBs active 5 passive
Server 2 Site 2 hosts 5 DBs active 5 passive

Furthermore:
Server 1 Site 1 hosts 5 DBs passive from Site 2 Server 1
Server 2 Site 1 hosts 5 DBs passive from Site 2 Server 2
Server 1 Site 2 hosts 5 DBs passive from Site 1 Server 1
Server 2 Site 2 hosts 5 DBs passive from Site 1 Server 2


Just size SAN IO properly to accommodate any one server running 10 local DBs as well as 5 DR remote site DBs at the same time. Size HW accordingly as well.

Provides you with 2 local copies as well as a remote (lagged) copy and utilizes all hardware.




luke.denham -> RE: 2 MBX servers, Single DAG, Multi Database, Multi Site Active/Active HA ... (21.Oct.2010 5:05:19 PM)

Thanks for your reply!

The difference with your solution is that your data centres are active / passive, so I assume your FSW is in the "active" data centre.

I believe from my research that in an Active/Active data centre scenario (with a shared subnet), if the link between the data centre fails, the MBX server in the data centre with the FSW enables the passive DB (thereby running both DBs) while the MBX server in the other data centre dismounts it's DB as it lost connection to both the FSW and the other MBX server. When the link is re-established DAC kicks in to prevent the MBX server seizing back the DB so that is a manual process.




Page: [1]